UE4 - In app purchase inssue

Hi, Im trying to configure my game to work with google play services.
I already changed the DefaultEngine.ini to enable in app purchase.
Filled the project settings at android settings with my store id and game id.
When I try to purchase a item, it fails everytime. When I try to purchase a item using my phone, it gets a authentication error.

In phone error:

http://puu.sh/iLiqI/0d68ed4c73.png

My project configs:

http://puu.sh/iLiDO/0bf79ad84a.png

My DefaultEngine.ini:

http://puu.sh/iLiFT/03e7307669.png